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Topic: Original battery hold down bolt (Read 8969 times)

Could someone please help me by posting a picture of a correct battery hold down bolt. When I purchased my 69 Z28 it was missing the battery hold down and bolt. I purchased an original gm battery hold down and an amk under hood detailing kit which includes the battery hold down bolt. The bolt in the kit seems to be too short. I purchased a sealed R59 battery and I cannot seem to get this bolt to work. Thanks for the help.

Seems to be two points of view here and in other threads I have looked at.Let's look at the facts as presented in the AIM'sSame part number 3758783 and torque used in all three years of production for this particular bolt.Why would the torque of 60-80 in lbs (6.6 ft lbs) be applied to this bolt when the same size bolts in the same area have 120-180 in lbs (12 ft lbs) applied to them.I believe that the toothed conical washer was specified and thus the lower torque value.If anyone has ever tried to change a battery in a first gen then you know why the lead point on the bolt was specified, especially with AC (67-68). I bring these points of view, not to start an argument, but to reason why this particular bolt does not have an accepted specific style and measurement.Thanks,Bob

Same part number 3758783 and torque used in all three years of production for this particular bolt.Why would the torque of 60-80 in lbs (6.6 ft lbs) be applied to this bolt when the same size bolts in the same area have 120-180 in lbs (12 ft lbs) applied to them.

On the battery hold-down application, the bolt is bearing down (through the clamp) on a molded tab that's part of the plastic battery case - a "soft make-up" application; too much torque, you break the case and have acid everywhere. Other applications using the same bolt join two steel parts, with "hard make-up" joints.

Same part number 3758783 and torque used in all three years of production for this particular bolt.Why would the torque of 60-80 in lbs (6.6 ft lbs) be applied to this bolt when the same size bolts in the same area have 120-180 in lbs (12 ft lbs) applied to them.

On the battery hold-down application, the bolt is bearing down (through the clamp) on a molded tab that's part of the plastic battery case - a "soft make-up" application; too much torque, you break the case and have acid everywhere. Other applications using the same bolt join two steel parts, with "hard make-up" joints.

John,How would the bolt stay tight at half of it's recommended torque?Is the plastic case compressing and compensating for the lack of bolt stretch or are the teeth on the conical washer keeping the bolt tight?Bob

John,How would the bolt stay tight at half of it's recommended torque?Is the plastic case compressing and compensating for the lack of bolt stretch or are the teeth on the conical washer keeping the bolt tight?Bob

"Recommended torque" on a fastener is determined by Fastener Engineering based on the type of joint and the joint materials involved; the fastener's job is to establish and maintain clamping force in the joint, and the torque required to do that is a function of the materials in the joint.

John,How would the bolt stay tight at half of it's recommended torque?Is the plastic case compressing and compensating for the lack of bolt stretch or are the teeth on the conical washer keeping the bolt tight?Bob

"Recommended torque" on a fastener is determined by Fastener Engineering based on the type of joint and the joint materials involved; the fastener's job is to establish and maintain clamping force in the joint, and the torque required to do that is a function of the materials in the joint.

In this case was the conical toothed washer used to maintain clamping force because of the soft joint? If not, why was toothed washer specified in this case?Bob

John,How would the bolt stay tight at half of it's recommended torque?Is the plastic case compressing and compensating for the lack of bolt stretch or are the teeth on the conical washer keeping the bolt tight?Bob

"Recommended torque" on a fastener is determined by Fastener Engineering based on the type of joint and the joint materials involved; the fastener's job is to establish and maintain clamping force in the joint, and the torque required to do that is a function of the materials in the joint.

In this case was the conical toothed washer used to maintain clamping force because of the soft joint? If not, why was toothed washer specified in this case?Bob

Are you referring to the battery hold down bolt #3758783 Bob? It did not have a conical toothed washer that I'm aware of, just that oversize captured washer.

Chick,Yes.The questions I have asked have arisen from reply #1 which indicates two types of bolts being used on survivors but only one type was factory specified.Just trying to find an engineering answer to my reply #6 and now reply #10.Bob

John,How would the bolt stay tight at half of it's recommended torque?Is the plastic case compressing and compensating for the lack of bolt stretch or are the teeth on the conical washer keeping the bolt tight?Bob

"Recommended torque" on a fastener is determined by Fastener Engineering based on the type of joint and the joint materials involved; the fastener's job is to establish and maintain clamping force in the joint, and the torque required to do that is a function of the materials in the joint.

In this case was the conical toothed washer used to maintain clamping force because of the soft joint? If not, why was toothed washer specified in this case?Bob

I guess you'd have to ask the responsible release engineer about the specifics.